Pressure vessel



June 1967 J. H. MERCIER 3,326,241

PRESSURE VESSEL Filed Jan. 13, 1965 2 Sheets-Sheet 1 I ATTaE NE 75 June 20, 1967 J. H. MERC|ER PRESSURE VESSEL 2 Sheets-Sheet 2 Filed Jan. 13, 1965 will United States Patent 69 13 Claims. (Cl. 13830) This invention relates to the art of pressure vessels, more particularly of the bladder type.

The present invention is directed to pressure vessels of the type, for example, comprising a substantially cylindrical container having opposed axial ports with a bladder of resilient deformable material intervening between said ports and defining a fluid chamber on each side thereof. The bladder has a mouth at one end secured to one of said ports for charging of the associated chamber defined by the interior of the bladder with one fluid under pressure and the other chamber defined between the exterior of the bladder and the inner surface of the container is charged with a second fluid under pressure through the other port.

When the cylindrical container is positioned vertically with the bladder port at the lower end thereof and the chamber defined by the bladder is charged with a gas and the other chamber with oil for example, or there is a difference in the density between the fluids in the two chambers, and the bladder chamber is charged with the lower density fluid, the free end of the bladder will float and tend to adopt a mushroom shape.

Thus, for example, when a valve controlling the port in communication with the oil chamber is opened for discharge of the oil in the oil chamber, the free expanded end of the bladder will rise suddenly toward the oil port. As a result, there will be a strong sudden pulling action at the region of attachment of the mouth of the bladder to the gas port which tends to pull the mouth of the bladder away.from such attaching means with resultant failure of the unit.

It is accordingly among the objects of the invention to provide a bladder type pressure vessel of the above type which may be used with the free end of the bladder directed upwardly and in which the pulling action or forces exerted by the mouth of the bladder on the retaining means therefor, with opening of the oil port of the pressure vessel will be minimized, thereby to prevent disconnection of the bladder mouth from its retaining means with resultant, failure of the unit. I

According to the invention, these objects are accomplished by the arrangement and combination of elements hereinafter described and more particularly recited in the claims. I

In the accompanying drawings in which are shown one or more of various possible embodiments of the several features of the invention,

FIG. 1 is a longitudinal sectional view of a pressure vessel according to one embodiment of the invention,

FIG. 2 is a view similar to FIG. 1 showing the gas chamber defined by the bladder of the pressure vessel in compressed compressed extended condition,

FIG. 3 is a view of the retaining means for the bladder on an enlarged scale and with the bladder expanded,

FIG. 4 is a view similar to FIG. 3 but with the bladder compressed,

FIG. 5 is a view similar to FIG. 1 of another embodiment of the invention,

FIG. 6 is a detail sectional view taken along line 6-6 of FIG. 5,

FIG. 7 is a view of the retaining means of the bladder of FIG. 5 on an enlarged scale and with the bladder expanded,

FIG. 8 is a view similar to FIG. 6 but with the bladder compressed, and

FIG. 9 is a view similar to FIG. 1 of still another embodiment of the invention.

Referring now to the drawings, as shown in FIG. 1, the pressure vessel comprises a cylindrical container 10 of strong rigid material having substantially hemispherical ends 11 and 12, each having a port 13, 14 which are axially aligned as shown.

Positioned in the port 13 is a fitting 15 which serves to retain a flexible partition 20 in the form of a bladder in secure position in the container 10.

The fitting 15 comprises a circular disc portion 16 having an axial stem 17, the periphery of the disc portion having an annular groove 19, an annular shoulder 37 being defined between the groove 19 and said stem 17. The bladder 20 which preferably is of rubber, natural or synthetic, has a relatively small diameter mouth with an annual head 21 designed to seat in said groove 19. Thus, when the stem 17 is inserted through port 13 and a nut 18 screwed on the threaded protruding end of the stem is tightened, the bead 21 will be clamped between the groove 19 and the adjacent wall surface of the container 10. Thus, the mouth of the bladder will be securely retained in fixed position, the shoulder 37 abutting against the container wall to limit the movement of the fitting 15 when the nut 18 is tightened, thereby preventing cutting of the mouth of the bladder 10.

The fitting 15 has an axial bore 22 which illustratively is internally threaded as at 33 to receive the correspondingly threaded hollow stem 23 of a clamp member 31.

As shown in FIG. 3, for example, the clamp member 31 has a circular flange portion 34 with a reduced diameter annular hub 32 defining a shoulder 36 adapted to seat on the inner end of fitting 15 and a resilient takeup disc 29 of rubber, for example, which preferably is harder than the material from which the bladder 20 is formed, encompasses annular hub 32 and is compressed between the flange portion 34 of the clamp member 31 and the inner end of fitting 15 when the shoulder 36 abuts against such inner end.

The diameter of the flange portion 34 of the clamp member 31 is less than that of the resilient disc 29 and the diameter of the resilient disc is greater than that of the disc portion 16 of the fitting 15 and preferably is of diameter such as to retain the wall portion 38 of the bladder 20 adjacent its mouth against the wall of the container 10.

In the illustrative embodiment shown, the diameter of port 14 is greater than that of port 13 and also greater than that of the flange portion 34 of the clamp member 31 so that the latter with the mouth of bladder 20 encompassing the disc portion 16 of the fitting 15, may be inserted through port 14 and the fitting 15 secured in port 13.

The port 14 has an outlet member 24 secured therein for flow of fluid, such as oil therethrough. Such outlet member may be of any suitable type such as that shown in U.S. Patent No. 2,924,244 and has a spring urged poppet member 25 associated therewith which is designed to close when the inflated bladder 20 presses thereagainst to prevent extrusion of the bladder.

As such outlet member 24 may be of any suitable type and per se, forms no part of this invention, it will not be further described.

Although the present invention has utility regardless of the position of the pressure vessel, it is of special importance when the pressure vessel is utilized with the outlet Inember 24 which defines the oil port, is at the upper end of the unit.

In operation, the chamber 39 defined by the bladder is first charged with a fluid such as gas under pressure through the fitting 15 until the bladder expands substantially to fill the interior of the container, and a valve (not shown) controlling the bore 35 of fitting 15 is then closed. Thereupon, a second fluid such as oil under pressure greater than that in chamber 39 is forced through outlet member 24 to charge the chamber 40 defined between the container wall and the bladder 20. Thus, the bladder 20 and the gas contained therein will be compressed. When the chamber 40 is charged, a valve 26 controlling member 24 is closed.

With the bladder compressed, since it is filled with gas under pressure, it will tend to assume the shape shown in FIG. 2, i.e., the bladder will be elongated and the gas will tend to be forced to the upper free end of the bladder which is floating in the denser oil. Thus, the bladder will assume substantially a mushroom shape with a narrow neck 27 near the fitting 15 and an enlarged globular portion 28 at the free end of the bladder.

When the valve 26 is opened for discharge of oil from the chamber 40, due to the sudden decrease in pressure in the oil chamber 40, the end 28 of the bladder will rise suddenly toward outlet member 24 causing a large force to be exerted against the neck portion 27 thereof, and in the absence of the invention hereof, against the bead 21 in groove 19, which might pull the head from such groove with resultant failure of the unit.

However, by reason of the flexible or resilient disc 29,

the peripheral portion 30 thereof tends to retain the portion 38 of the bladder wall adjacent bead 21 against the wall of the container, so that little force is transmitted to the bead 21 so that it will be dependably retained in position by the fitting 15. Due to the resilience of the disc, the periphery 30 thereof will yield slightly as shown in FIG. 4 thereby preventing injury to the portion of the bladder wall engaged by such periphery 30.

After the sudden surge of fluid, due to initial opening of valve 26, has ceased, and normal flow proceeds, the resilient disc 29 will assume its normal configuration as shown in FIG. 3.

The embodiments shown in FIGS. and 9 are similar in many respects to the embodiment shown in FIG. 1 and corresponding parts have the same reference numerals primed.

The embodiments of FIGS. 5 and 9 are especially designed for use where the pressure vessels and the bladders therein are relatively long and are designed to prevent the formation of sharp folds in the bladder when it is compressed, which could cause rupture of the bladder.

Referring to FIGS. 5 to 8, the fitting 15' is substantially identical to the fitting 15 of FIG. 1 except that the bore 22' of fitting 15' is not internally threaded but has a reduced diameter portion ,41 at its inner end defining an annual shoulder 42. A sleeve 43 flanged at its outer end as at 44 is positioned in the bore of the fitting 15 until i the inner end of sleeve 43 abuts against shoulder 42 and the sleeve 43 is retained in place as by snap ring 45.

The sleeve 43 is internally threaded to receive the end of a tightly wound relatively, rigid coil spring 46 which extends axially ofthe container. A porous tube 47, preferably of sintered metal, closed at its upper end as at 48 is secured to the free end of the coil spring as by encompassing one end of a nipple 49, the other end of which is forced into the bore of the coil spring.

Encompassing the coil spring 46 at its root end is a takeup member 51, illustratively frusto conical in shape and having an axial bore 52 through which the spring 46 extends, the spring being snugly engaged by the takeup member 51.

The takeup member 51, which is of resilient material suchas rubber, has its base 53 resting against the inner end surface of the fitting 15 and the diameter of the base is greater than that of the disc portion 16' of the fitting 15 so that the rounded periphery 54 of the base will extend outwardly of the periphery of the fitting 15'.

The gas chamber 39' defined by the bladder of FIG. 5 is charged by forcing gas under pressure through the fitting 15.

Such gas will readily flow from the bore of the coil spring 46 between the'adjacent convolutions thereof into the bladder 20 to charge the latter.

Thereupon, the oil chamber 40' defined between the bladder and the container wall is charged with oil under pressure greater than that in the gas chamber 39.

As the oil under pressure is forced into the container 10' it will compress the bladder 20 and the gas therein. However, by reason of the coil spring which extends axially of the container, the lower portion of the bladder will tend to press against the coil spring preventing sharp folds forming in such bladder.

The upper portion of the bladder will tend to form a globular shape as described with respect to the embodiment of FIG. 1 and when the valve 26' controlling outlet member 24 is opened the free end of the bladder will rise suddenly toward said outlet member.

However, as the lower end 57 of the compressed bladder is pressed against the conical side wall 58 of resilient member 51, the sudden pulling of the bladder will be taken up by the bending of the rounded periphery 54 of the base of member 51 as shown in FIG. 2 so that little or no pulling will be imparted to the head 21. Hence, the head will remain securely clamped in groove 19' in fitting 15'. When the surge, due to the initial opening of valve 26 stops and normal flow occurs, the periphery 54 of member 51 will assume its normal position.

When the chamber 39' defined by the bladder is fully compressed, the bladder 20 will be snugly retained against the central spring 46 and takeup member 51 as shown in FIG. 8. Due to the floating of the upper end of the bladder 20' in the fluid in chamber 40', when the pressure vessel is utilized for example, to transfer fluid from chamber 40 by forcing a second fluid under pressure through fitting 15' into the bladder 20, such second fluid will pass through the coil 46 into the bladder and would tend to flow more readily through the upper end of the coil spring into the upper enlarged portion of the bladder. However, since the periphery 54 of member 51 is under stress at this time (as shown in FIG. 8) it tends to resume its normal condition as shown in FIG. 7 and pulls the bladder near its secured end. This tends to space the bladder from the coil spring near the lower end of the latter so that fluid can also enter the bladder near its aflixed end. As a result, the bladder will expand more uniformly along its length as it is charged, hence minimizing the possibility of rupture.

The embodiment shown in FIG. 9 is similar to that shown in FIG. 5 except that the central guide member for the bladder is a perforated rigid tube 61 instead of a coil spring.

Since the operation of the embodiment of FIG. 9 is the same as that of the embodiment of FIG. 5, it will not be described.

With the constructions above described, a pressure vessel is provided in which the bladder may be dependably clamped in position with assurance that sudden longitudinal pull on the bladder will not cause the mouth of the bladder to become disengaged from the fitting by which such mouth is retained in place and more particularly when the pressure vessel is used in inverted position with the free end of the bladder directed upwardly and also will provide for more uniform expansion of the bladder to prevent rupture thereof.

. As many changes could be made in the above constructions, and many apparently widely different embodiments of this invention could be made without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A pressure vessel comprising a rigid container having longitudinally aligned ports, a bladder of deformable material positioned in said container and defining a pair of chambers in communication respectively with said ports, one of said chambers being defined by the interior of said bladder, said bladder having a port, means clamping the periphery of said bladder port in said container in fixed position with respect to one of said container ports and resilient means to dampen the forces exerted against the clamped periphery of said bladder when the other port of said container is initially opened for discharge of fluid from the chamber in communication with said other port.

2'. The combination set forth in claim 1 in which said resilient means comprises a circular member of resilient material secured in said bladder adjacent the port thereof and coaxial therewith, the diameter of said circular resilient member being greater than that of the clamping means, the portion of said bladder Wall adjacent said bladder port abutting against the periphery of said circular elastic member.

3. The combination set forth in claim 2 in which said circular member is a flat disc.

4. The combination set forth in claim 2 in which said circular member is frusto-conical having its wider diameter base adjacent the clamping means.

5. The combination set forth in claim 1 in which said first container port has a fitting with a circular disc having an annular groove, said bladder port has an annular bead positioned in said annular groove and clamped between the groove and the adjacent wall surface of said container, and a circular member of resilient material is secured to said fitting internally of said bladder and coaxial therewith, said resilient member being of greater diameter than that of the fitting disc, whereby the periphery of said resilient member will protrude beyond the periphery of said disc and will engage the portion of the bladder wall adjacent the bladder port to dampen the forces exerted against the clamped periphery of the bladder when said other port of the container is initially opened.

6. The combination set forth in claim 5 in which said fitting has an axial bore, a clamp member is provided having a circular flange with an axial stem in the fitting bore, said clamp member having an axial bore, said clamp member having a reduced diameter portion between the flange thereof and the stem, said resilient member is a disc encompassing said reduced diameter portion and clamped between the flange and the adjacent end of said fitting.

7. The combination set forth in claim 1 in which said bladder is inflated but unstretched condition has its free end slightly spaced from the port remote from the port to which the port of the bladder is secured.

8. The combination set forth in claim 2 in which a central guide member has one end secured in fixed position adjacent the first container port and extends axially of said container, the free end of the guide member being positioned in said bladder and spaced from the free end thereof, said guide member permitting passage therethrough of fluid from said first container port into said bladder, said circular member is frusto-conical having its wider diameter base adjacent the clamping means, the guide member extending axially from the frusto-conical member.

9. The combination set forth in claim 8 in which the frusto-conical resilient member has an axial bore and the guide member has one end positioned in said bore.

10. The combination set forth in claim 8 in which the frusto-conical resilient member has an axial bore, said guide member is a coil spring having closely wound convolutions and one end of the coil spring is positioned in said axial bore.

11. The combination set forth in claim 8 in which said fitting has an axial bore, a sleeve is secured in said axial bore, said sleeve being internally threaded, the frustoconical resilient member has an axial bore, said guide member is a coil spring having closely wound convolutions, one end of the coil spring is secured in the threaded bore of said sleeve and extends through the axial bore in said resilient member.

12. The combination set forth in claim 8 in which said fitting has an axial bore, a sleeve is secured in said axial bore, said sleeve being internally threaded, the frustoconical resilient member has an axial bore, said guide member is a coil spring having closely wound convolutions, one end of the coil spring is secured in the threaded bore of said sleeve and extends through the axial bore in said resilient member, a porous member is secured at one end with respect to the free end of said coil spring in said bladder, the free end of said porous member being closed.

13. The combination set forth in claim 8 in which said fitting has an axial bore, said guide member is a rigid perforated tube having one end secured in the bore of said fitting, the frusto-conical resilient member has an axial bore, said rigid tube extending through the axial bore in said frusto-conical member.

References Cited UNITED STATES PATENTS 3,209,785 10/1965 Mercier 138-30 3,211,184 10/1965 Greer 138-30 FOREIGN PATENTS 587,982 12/1959 Canada. 989,742 5/1951 France. 344,325 1/ 1960 Switzerland.

LAVERNE D. GEIGER, Primary Examiner.

T. L. MOORHEAD, Assistant Ex'aminer. 

1. A PRESSURE VESSEL COMPRISING A RIGID CONTAINER HAVING LONTIDUINALLY ALIGNED PORTS, A BLADDER OF DEFORMABLE MATERIAL POSITIONED IN SAID CONTAINER AND DEFINING A PAIR OF CHAMBERS IN COMMUNICATION RESPECTIVELY WITH SAID PORTS, ONE OF SAID CHAMBERS BEING DEFINED BY THE INTERIOR OF SAID BLADDER, SAID BLADDER HAVING A PORT, MEANS CLAMPING THE PERIPHERY OF SAID BLADDER PORT IN SAID CONTAINER IN FIXED POSITION WITH RESPECT TO ONE OF SAID CONTAINER PORTS AND RESILIENT MEANS TO DAMPEN THE FORCES EXERTED AGAINST THE CLAMPED PERIPHERY OF SAID BLADDER WHEN THE OTHER PORT OF SAID CONTAINER IS INITIALLY OPENED FOR DISCHARGE OF FLUID FROM THE CHAMBER IN COMMUNICATION WITH SAID OTHER PORT. 